1. Field of the Invention
The invention relates to a magnetic sweeper for picking up magnetic metal objects scattered on a surface, more particularly to a magnetic sweeper that is simple in construction, and that is easy to operate.
2. Description of the Related Art
Magnetic metal objects, such as nails, nuts, screws, springs, studs, clips, etc., are likely to drop to the floor when in use. In a clean and small space, they can be picked up with bare hands with relative ease. However, it is troublesome to remove such metal objects from a spacious area, such as a yard, a lawn, a work site, and the beach, or small and narrow spaces, such as the ground beneath a car""s chassis. There is available a type of magnetic sweeper, such as that shown in FIG. 1, for removing magnetic metal objects from a surface. The magnetic sweeper as shown includes a suction disk 1, a magnet 2 adhered to a bottom side of the suction disk 1, and a handle 3 extending upwardly from a top side of the suction disk 1. In use, the magnetic sweeper is moved along the surface by means of the handle 3, and magnetic metal objects on the surface will be captured by means of the magnetic force of the magnet 2.
A major drawback associated with the above-described magnetic sweeper is that, after a certain amount of metal objects are captured by the magnet 2, the user has to remove them from the magnet 2 one by one, which is very troublesome. Moreover, the user may be pricked by pointed ends of the captured metal objects. In addition, due to the length of the handle 3, the above-described magnetic sweeper cannot access places of a small height. Besides, the magnetic sweeper is bulky and is hence inconvenient to maneuver.
U.S. Pat. No. 4,407,038 discloses a magnetic sweeper that includes a main body member having end walls 16 on which wheels 26 are pivotally mounted. The magnetic sweeper disclosed therein permits relatively easy operation. However, it is inconvenient to remove metallic objects captured by magnets 42.
U.S. Pat. No. 5,285,904 teaches a magnetic sweeper including a catcher member 34 which is manually removable to permit metallic objects picked up by magnetic attraction and held against the catcher member 34 to fall away and into a receptacle for discard. However, the user""s hand maybe pricked or cut by pointed ends of the metallic objects when removing the catcher member 34.
Therefore, the main object of the present invention is to provide a magnetic sweeper that is simple and easy to construct and assemble, and that overcomes the drawbacks associated with the prior art.
Accordingly, a magnetic sweeper of this invention is adapted to be rolled over a surface to pick up magnetic metal objects scattered thereon. The magnetic sweeper includes a mounting frame, a rotating shaft, a cylindrical body, a plurality of magnetically attracting members, a guiding member, a collecting member, a mounting axle, a wheel member, and a coupling member. The mounting frame has left and right side walls spaced apart from each other in an axial direction. The rotating shaft defines an axis, and has left and right ends that are disposed to be respectively journalled in and to extend outboard to the left and right side walls. The cylindrical body is mounted to be rotated with the rotating shaft, and has an outer circumferential wall which surrounds the rotating shaft and which defines a rotating path when the cylindrical body is rotated with the rotating shaft. The magnetically attracting members are disposed in the outer circumferential wall, and are angularly displaced from one another and around the rotating shaft so as to form uppermost and lowermost magnetic linear limits on the rotating path. The uppermost and lowermost magnetic linear limits are diametrically spaced from each other relative to the axis. The guiding member is made of a nonmagnetic material, and includes left and right lateral edges, and a major wall. The left and right lateral edges are opposite to each other in the axial direction and are secured respectively to the left and right sidewalls. The major wall is interposed between the left and right lateral edges, and extends in a transverse direction relative to the axial direction to define leading and tailing ends and an intermediate portion interposed therebetween. The major wall is configured to have a profile such that the leading and tailing ends are respectively spaced outwardly and non-equidistantly from the uppermost and lowermost magnetic linear limits. As such, the magnetic metal objects captured by means of magnetic force at the lowermost magnetic linear limit and adhered to the tailing end slide over the intermediate portion by rotation of the cylindrical body, and fall down by virtue of their own weight once the magnetic metal objects proceed beyond the uppermost magnetic linear limit where the magnetic force is weaker than gravity. The collecting member is disposed downstream of and below the uppermost magnetic linear limit to receive the magnetic metal objects that drop thereinto. The mounting axle is disposed on the mounting frame to extend in the axial direction, and is spaced apart from the rotating shaft. The wheel member is rotatably mounted on the mounting axle and is adapted to roll over the surface. The coupling member is disposed to transmit rolling movement of the wheel member to one of the left and right ends of the rotating shaft so as to rotate the cylindrical body.